Health - Glass in pot?

[libertalism]

Hello , swim's friend has bought a baggie today and while rolling a j of it , while sitting next to the seller, ( who bought it off a unofficial coffeeshop ) he found quite a big piece of glass on his joint ( about half a cm ) . He asked "wtf , is there glass in this pot? " ( he is friends with the seller btw ) then the seller told him that it was allready lying there and it must have flew on it or something . Swim's friend took his word for it and smoked the j with his seller.
When swim's friend got home he was getting kinda paranoid and tried looking here for easy noticable ways to tell if there is infact glass in it.
He searched his bag for more big pieces of glass but found nothing and also looked for the blinky thc kinda things. He only found a few. The pot is kinda sticky tho and from ok quality ( about X-X euros worth in the shops ).
What should he do?

[libertalism]

Swim also remembers having bought buds with sand , just of a random guy. After smoking the bag there was clearly a layer of sand at the bottem of the bag. He also coughed up blood( in slimes & spit ) for a few days in that period but he isn't sure if that was related.
He didn't know that sand was dangerous at that time so he didn't really make the link.

[Methadrone]

Swim has known of cases of dealers throwing sand in with buds to make it heavier, this is terrible as it can kill you if it gets onto the lungs swim has had to throw some grass away as this had been done. better that than be dead.